Methodology Development for EDM Vibro-acoustic Assessment using Simulation Measurement Comparison and RCA

The virtual development of Electric Drive Modules (EDM) for Battery Electric Vehicles (BEVs) requires proven and predictive methodologies. One part of the development investigates the vibro-acoustic assessment for low and high frequencies over the targeted operating range. The efficient usage of such a methodology requires the understanding of the accuracy and the validity of the achievable results as well as the derivation of suitable improvement measures for goals that have not been achieved. The usage of reference data from experimental investigations and a detailed root-cause analysis (RCA), to directly link a specific response and behavior to the excitations, modal content and transfer functions, is an essential and non-trivial part of the methodology development. This paper describes the development of such a methodology using the example of a new EDM virtual model for Noise, Vibration and Harshness (NVH) analysis, the simulation approach, validation, and evaluation procedure. It is discussed how RCA can be applied to different observed phenomena for EDM NVH behavior and detected deviation between the initial model and the measurements, the main influencing parameters, and the detected improvement potential for simulation models. The applied Multi-body dynamics (MBD) methodology is validated through the comparison of simulated vibrational and acoustic level with measured data. The simulation model is than improved by applying root cause analysis methods, that can be also used to identify design recommendations in the early design stage before physical prototypes exist.